In recent years, millimeter wave wireless communication using a 60 GHz band has attracted attention. A study directed to development of the IEEE 802.11ad, which is an advanced standard for using the 60 GHz band, has been executed also at The Institute of Electrical and Electronics Engineers, Inc. (IEEE) 802.11, which is a wireless Local Area Network (LAN) standard, (see NPL 1).
The 60 GHz band has characteristics that ultra-high-speed transmission is possible but a communication service area is narrower compared to a 2.4 GHz band or a 5 GHz band of a microwave which is widely used in a wireless LAN in the related art. Therefore, a communication method is useful which performs ultrafast communication using the 60 GHz band in a communication service area of the 60 GHz band and performs communication using the 2.4 GHz band or the 5 GHz band in communication service areas other than that of the 60 GHz band, by using multi-band devices available for multiple frequency bands. PTL 1 discloses a method of Fast Session Transfer (FST) by which a multi-band device exchanges information, for example, a switching timing and a switching target frequency band, with a peer station, which is a wireless station of a communication partner, so as to perform a switching procedure, when the multi-band device uses frequency bands while being switched.